Problem: Reduce to lowest terms: $- \dfrac{3}{8} \div - \dfrac{5}{3} = {?}$
Explanation: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $- \dfrac{5}{3}$ is $- \dfrac{3}{5}$ Therefore: $ - \dfrac{3}{8} \div - \dfrac{5}{3} = - \dfrac{3}{8} \times - \dfrac{3}{5} $ $ \phantom{- \dfrac{3}{8} \times - \dfrac{3}{5}} = \dfrac{-3 \times -3}{8 \times 5} $ $ \phantom{- \dfrac{3}{8} \times - \dfrac{3}{5}} = \dfrac{9}{40} $